(1) Field of the Invention
The present invention relates generally to textile fabrics and, more particularly, to a double-faced warp knit fabric for performance applications.
(2) Description of the Prior Art
Prior art double-faced warp knit fabrics are commonly found to be pile fabrics, i.e., to realize a difference on the face and back sides, a warp-knitted pile fabric manufacturing machine employs an auxiliary mechanical device, such as a plush needle bar. However, this pile fabric is limited in terms of the quality that differs from face to back: it is only capable of producing a plush face side and a back side, i.e., only a single quality difference is possible to realize from this fabric-forming method. Examples of pile fabric found within the relevant art include the following:    U.S. Pat. No. 3,710,598 issued Jul. 16, 1973 to Wilkins for a Pile fabric method.    U.S. Pat. No. 3,043,124 issued Jul. 10, 1962 to Hubbard for a Knitted pile fabric.    U.S. Pat. No. 2,957,327 issued Oct. 26, 1960 to Glover for a Warp knitted pile fabric.    U.S. Pat. No. 2,696,723 issued Dec. 14, 1954 to Frith for a Locked pile fabric.    U.S. Pat. No. 1,801,825 issued Apr. 21, 1931 for a Plush warp knit fabric.
Other examples of double-faced warp knit fabrics commonly employ multilayer fabrics, i.e., are not single layer fabrics, and, in particular relate to velvet fabrics or velour fabrics having at least two layers, and spacer fabrics, which “sandwich” an additional layer of spacer yarns between the two sides or faces of the fabric. In these cases, while the fabrics may be constructed to include different qualities on the face and back, the fabrics have a thickness dimension that limits the applications of the fabric, and/or limits the characteristics of the fabric, e.g., by increasing the weight of the fabric, and often the stiffness due the increase in fabric thickness. From the standpoint of the present invention, these properties associated with multilayer fabrics are not desirable.
Examples of multilayer double-faced warp knit fabrics include the following:    U.S. Pat. No. 6,634,190 issued Oct. 21, 2003 to Didier-Laurent for a Double-faced thick knitted fabric with flexible structure. A thick double-face knitted fabric has a front face (1) and a rear face (2), which are connected to one another by an intermediate layer (3), and is produced on a circular knitting machine. The intermediate layer (3) is produced solely from binding monofilaments. The knitted fabric which is produced has the qualities of flexibility and of elasticity, and a minimum thickness of 3 mm. A knitting method and a machine for producing the knitted fabric are also disclosed.    U.S. Pat. No. 6,199,410 issued Mar. 13, 2001 to Rock, et al. for a Double face warp knit fabric with two-side effect. A fabric with a patterned velvet on one face and a different patterned velour on the other is formed from a three dimensional fabric using a double bar knitting machine. Preferably, at least either the stitching or backing yarn within the fabrics is made with a bulk high enough so that after the three dimensional structure is knitted and split, the back can be napped to form the velour from such yarn.    U.S. Pat. No. 6,196,032 issued Mar. 6, 2001 to Rock, et al. for a Double face warp knit fabric with two-side effect. A fabric with a patterned velvet on one face and a different patterned velour on the other is formed from a three dimensional fabric using a double bar knitting machine. Preferably, at least either the stitching or backing yarn within the fabrics is made with a bulk high enough so that after the three dimensional structure is knitted and split, the back can be napped to form the velour from such yarn.    U.S. Pat. No. 6,131,419 issued Oct. 17, 2000 to Rock, et al. for a Two face cut loop fabric. A cut loop fabric, knit on a conventional terry knitting machine utilizing a reverse plaiting technique, is provided. The fabric has a technical face with a raised or napped surface, and a technical back in which the sinker loops are sheared in order to form a cut loop velvet surface.    U.S. Pat. No. 6,446,472 issued Sep. 10, 2002 to West, et al. for a Fabric structure with stand-off design. A fabric including raised members that effectively separate the wearer from the fabric base. The raised members add a third dimension of depth or thickness to a traditionally two-dimensional piece of apparel allowing the fabric base to remain separate from the wearer's body which provides greater comfort and breathability to the wearer. The raised members may be placed in useful proportion with open holes or closed spaces of the fabric enhancing the quality and functionality of the apparel.    U.S. Pat. No. 6,427,493 issued Aug. 6, 2002 to Kasdan, et al. for a Synthetic knit fabric having superior wicking and moisture management properties A weft knit synthetic fabric having an irregular pique construction prepared on a double knit machine having four feeds, two of which are microfiber yarn and two of which are regular non-microfiber yarn. The fabric is formed with at least 40 weight percent microfiber yarn and the balance conventional non-microfiber yarn which is worn against an individual's body for maximum moisture absorption with the microfilament knit on the face to provide maximum siphon to remove the moisture from a wearer's body. The knit fabric is stated to be particularly well suited for athletic wear.    U.S. Pat. No. 5,916,273 issued Jun. 29, 1999 to Hepfinger for a Warp knitted plush fabric. A warp-knitted fabric of at least three-bar construction, which is comprised of multifilament synthetic pile yarns on the technical back which are raised or broken to produce a plush surface and monofilament synthetic ground yarns on the technical face, the pile yarns being comprised of microdenier filaments having a denier no greater than 1.1.    U.S. Pat. No. 5,855,125 issued Jan. 5, 1999 to Lohmueller, et al. for a Method for constructing a double face fabric and fabric produced thereby. A method of constructing a double face fabric is provided. The first step in the method is to knit a three dimensional knit fabric which has a first fabric layer, a second fabric layer and a plurality of yarns that interconnect the two layers. The three dimensional knit fabric is prepared using a conventional double needle bar warp knitting machine. Then, the yarn connecting the two layers is cut, resulting in two pieces of fabric having a velvet surface on one side, and a flat knit surface on the other. The flat knit surface is then raised by a process such as napping to pull portions of the pile yarns through the fabric layer to the technical back, in order to form a pair of double face fabrics, each with a first velvet surface and a second fleece surface. Preferably, the fabric is knit so that after napping it can be stretched. In this manner a wide variety of fabrics can be created.    U.S. Pat. No. 5,727,401 issued Mar. 17, 1998 to Stafham for a Fire resistant fleece fabric and garment. A fire resistant fabric (10) suitable for use as an inner thermal barrier layer in a layered firefighters' turnout garment (30). The fabric is a 3-end knit fleece having stitch yarns (12), tie yarns (14), and nap yarns (18), all made of fire resistant fibers. The nap yarns are pulled away from the stitch and tie yarns to form a fleece.    U.S. Pat. No. 5,657,648 issued Aug. 19, 1997 to Ives, et al. for a Elastic fabric and method of making same. An elastic web fabric and method for producing the same. The resulting fabric is curl-free and has bi-directional stretch of between about 50-125% stretch in the width direction and 50-200% stretch in the length direction. In the preferred embodiment, the fabric includes a center marker formed from a two-needle shift of two rubber yarns to provide a centering line to aid in assembly of a finished article. Also, in the preferred embodiment, the left top edge of the fabric has about six rubber yarns and the right top edge has about 5 rubber yarns to prevent curling to produce a fabric which is more easily cut and fabricated into the finished article.    U.S. Pat. No. 5,528,910 issued Jun. 25, 1996 to Azais for a Double-faced weft knitted fabric, notably for leisure clothes. The double-faced knitted fabric, notably for leisure clothes, according to the invention, has one face with a surface in a first material, preferably cotton, whether pure or in a mixture, and the other face with a surface in a second material, preferably wool, whether pure or in a mixture. The knitted fabric is obtained on at least three feeds, two feeds with a full cardigan type knitting with a yarn of the first material and a second yarn of the second material and one feed with a jersey type knitting using a third yarn having the first material at least on the surface. In particular, this third yarn can be an elastic yarn, comprising for example, a covered elastomer yarn whose cover is in the first material.    U.S. Pat. No. 5,029,457 issued Jul. 9, 1991 to Gajjar for a Method of warp knitting. Wrap knit fabric having a two and three-course repeat pattern of alternating first and second, or first, second and third and first, second, third and fourth bar yarns. The fabric is prepared by interlocking the first and second or first, second and third bar yarns using a combination of knit and laid-in stitches in the same for two course, and same and opposite fashion for three and four course repeat.    U.S. Pat. No. 4,881,383 issued Nov. 21, 1989 to Spillane, et al. for a Warp knitted fabric with satin-like back and brushable face and method of knitting same. A three-bar warp knitted fabric having a brushable pile surface at its technical face and a satin-like surface at its technical back is produced on a three-bar warp knitting machine by knitting overfed pile yarns on the machine's bottom bar to produce brushable pile loops at the fabric's technical face, knitting satin-effect yarns on the machine's middle bar in extended underlaps to produce a satin-like technical back of the fabric and knitting relative smaller denier tie-down yarns on the machine's top bar in a chain stitch pattern to also extend at the fabric's technical back in crossing relationship to the satin-effect yarn underlaps to shield them from picking without significantly obstructing their satin-like appearance.    U.S. Pat. No. 4,811,573 issued Mar. 14, 1989 to Sternlieb for a Two face stitch bonded fabric. A decorative fabric has two faces and is made on two stitch through type machines of different gauge. The fabric has a non-woven, flexible substrate and a first plurality of spaced yarns laid on the front face of the substrate in the filling direction. First knitting threads of predetermined gauge form a series of warpwise loop chains which bind the first filling yarns and the substrate into an integral structure. The rear face of the substrate has a second plurality fo spaced yarns laid thereon in the filling direction, and second knitting threads of predetermined gauge which are different from the predetermined gauge of said first knitting threads, thereby forming a series of warpwise loop chains which bind the second plurality of spaced yarns and said substrate into an integral structure.    U.S. Pat. No. 4,712,281 issued December 1987 to Scheller for a Napped warp-knitted fabric and method of producing same. Warp knitted fabric of an at least two bar construction nappable on both fabric faces is produced on a warped knitted machine of at least three bar construction by utilizing a pile loop forming device on the bottom bar while simultaneously knitting a ground yarn substrate on the middle bar and knitting pile yarns on the top bar to be knitted into the substrate in needle loops at the technical fabric face and extended pile underlap loops at the technical fabric back. At least one surface of the fabric is napped, the extended underlap loops at the technical back being nappable to a plush surface effect while also being adapted to be partially drawn through the substrate to the technical face upon napping of the needle loops to produce a comparable plush surface at the technical face.    U.S. Pat. No. 4,567,075 issued Jan. 28, 1986 to Krawczyk for a Double faced knit fabric and method. A nappable, dimensionally stable fabric is produced on a three bar warp knitting machine by over feeding the yarns fed by the bottom bar to provide nappable loops, and by knitting the yarns fed by the top bar in a pattern providing nappable floats, longitudinal stability being provided by yarns knit from the middle bar, and lateral stability being provided by the partially napped floats.    U.S. Pat. No. 3,971,234 issued Jul. 27, 1976 to Rock, et al. for a Double-knit elastic fabric with raised patterns. An elastic double-knit fabric having alternating front and back wales knit from an elastic and inelastic yarn knit together in spaced patterns of adjacent stitches in adjacent front wales and in selected stitches in at least every fourth course in the back wales, all the remaining stitches in the fabric containing only inelastic yarn. This invention relates to weft-knitted fabrics and more particularly to double-knit fabrics in which elastic yarn is present in a stretched condition in the face and back stitches of preselected areas of the fabric. The elastic properties of spandex yarns enable manufacturers to produce a wide variety of fabrics ranging from foundation fabrics with outstanding holding power and figure control to outerwear, sportswear and underwear fabrics with excellent dimensional recovery providing ideal fit and comfort at all levels of body extension. In making elastic, double-knit fabrics, it is customary for the elastic yarn to be knitted in the back stitches of the fabric to reduce “grin through” and to make economical use of the elastic yarn. In the present invention, in addition to the back stitches, the elastic yarn is also selectively incorporated into face stitches, or front wales of a double-knit fabric producing fabric relief patterns without departing from the basic double-knit construction. According to this patent, this enables one to produce double-knit fabrics in which selected face stitches assume a more compact appearance or to produce fabrics with large areas of compact stitches in which the contraction of this area distorts the normal wale/course configuration to give curved courses maintaining relatively flat fabrics. In addition, double-knit fabrics can be produced in which certain areas are raised from the general fabric plane through the contracting action of the other areas.
Thus, there remains a need for a single layer double-faced warp knit fabric having different qualities on the face and back sides, and wherein the fabric is not a pile fabric.